Arrives before Christmas 
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Kit allows up to 15 amps from your RV's battery to be used to maintain the charge of your towed car's battery while the car is being towed. Charge line connects to the 6-way or 7-way plug on your vehicle. Requires separate charge line in RV.
Features:
California residents: click here
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hey everybody. Ryan here at etrailer. Today, on our 2022 Chevy Equinox, we're gonna be showing you how to install the Roadmaster battery charge line kit for towed vehicles. But before we do that, why don't we check this out and kind of go over why it's a good idea to use one of these. When it comes to setting up a flat tow, oftentimes, there's a handful of small components that are often kind of overlooked or forgotten about that you can use to make everything more complete, make your life a little bit easier, and have things set up the right way. And a battery charge line kit is one of those components.
And matter of fact, this is something that I don't only recommend for the Equinox, but just about every flat tow that I do, I always recommend one. And what this is gonna do is essentially trickle charge or maintain your vehicle's battery whenever you're flat towing it. And a lot of times, you can run your battery low because the vehicle's supplemental breaking system uses the battery power. And so, what can happen is, you know, you're over the road, six, eight, 10 plus hours. Over time, constantly just stealing a little bit of juice from the battery, it can wear this down and make it flat.
And so, you'll get to where you're going, try to disconnect, try to start the car, and it's dead, and then it's a big pain. You gotta deal with charging it, getting the jump box and your cables out, and everything else. So, having this charge line is gonna prevent all that. It's gonna keep your battery topped off and ready to use whenever you go to start the vehicle. Not to mention too, on newer cars nowadays, a lot of things are electronically controlled.
A lot of times, you'll have electric assist steering, electric assist brakes, and everything's computer controlled in a sense. And so, maintaining proper voltage is essential for a lot of those things to work. And with a dead battery, obviously, that's not gonna happen. So, a charge line will keep all that stuff kind of go into, I'm not sure if the Equinox uses all that type of stuff but just generally speaking. And another thing that this can help prevent is premature failure of your battery.
So, a battery will have so many cycles it can go through. So, if you drain this thing down and then fill it up, and drain it down and fill it up, drain it down, fill it up, that's going to decrease the overall life expectancy of it. So essentially, trickle charging this and keeping it topped off the whole time should really extend the life of the battery and keep it in good working condition. The way the kit is gonna work is really simple. It's gonna use some of your motorhome's auxiliary power coming out of the seven-way. That current's gonna flow up through here through a breaker. And this is just a circuit breaker. It's gonna protect everything in case there's a short or something along them lines. And then that current's gonna flow through the wire to your positive battery terminal. Now, you are going to have to have your car battery needs to be in good working condition. This isn't going to bring your battery back to life if it's already dead, or has a bad cell, or something along them lines. And it's not going to affect your motorhome's batteries either because your motorhome has its own charging system. It uses an alternator and there's extra amperage that is sent back to the seven-way that we can use. So, it's not gonna harm anything there or create any issues as far as that goes. Other than that though, at the end of the day, a small but really important component. This could really save you a lot of hassle in the long run. As far as getting it installed, it's really not bad. Essentially, it's two wires and really shouldn't run into too many issues. So, as long as you take the time, it really shouldn't give you any trouble. But speaking of that, why don't we go ahead and hook this stuff together now. To begin the installation for our charge line, we're gonna be here at the front of our vehicle. And clearly, we have the front fascia taken apart. That's because we're doing all this at the same time that we installed our base plate, which is what I recommend doing. We have all this extra room to work. I also suggest doing this the same time that you're doing your diode wiring because this is gonna route in a similar matter, a similar way. And you'll already be in the back of the connector plug here, so just save you a little bit of time. But with that said, you wanna take your charge line wire here, the red wire. Bring it down to where our connector plug is. You'll strip back the insulation a little bit. Something like that. Give those wires a good twist. And we're gonna hook this up to the center post on the back of our six-way connector. So, you just back out that set screw a little bit. Take the wire and carefully place it into the terminal there and then just tighten the set screw back down. Now, that we're hooked up, we can take our rubber boot, put it back over our six-way connector. And you can apply dielectric grease, and sealer, and stuff to the terminals inside there, and tape everything up and keep moisture out. I like to wait till the very end of a flat tow setup though to do that just so we can make sure everything's working and stuff. That way, If it's not, it's not a big mess in here. But for now, we'll go ahead and just mount this up to our base plate. And then the wiring is gonna get routed inside of the engine compartment. So, just ran it along through here and up where it comes in. Essentially, right underneath our headlight. So, here's where our charger and wire comes up in engine compartment. And this is gonna get routed to our breaker, which I have mounted right here. So, I just remove this nut using a 10 millimeter socket, put this over it, and tighten it down. So, these screws, or the nuts rather, on the breaker, go ahead and take those off. Careful with these. They're easy to drop and hard to find. So, we'll get them off. Then we're gonna take our wire and cut it to length. So, we'll go about right here. Cut that. Strip back the insulation. Take a small ring terminal then crimp that on. And then this is gonna go over the gold post. It's gonna be labeled battery, so you might be tempted to hook this up the other way, but since the motorhome is essentially acting as our battery, this is how we do it. We'll reinstall the nut. Come back with the a 3/8 socket and then snug it down. Then for our other wire here, we're gonna strip back both ends. One end we're gonna crimp on a small ring terminal and the other end is going to receive a large ring terminal. Get them connected. The small end will go over the silver post there. Get that tightened down. Once that's snug, this is gonna go over to our positive battery terminal. So, we should be able to pry this up. Let's see if I can get this whole piece off. Make it a little easier. And we will be connecting this to the positive terminal there. I'll take this off using a 10 millimeter. And a lot of times, these aren't designed to come completely off, at least very easily. And if that's the case, not a big deal. We have a way around it. Loosen this up and this is one of those. So, I'll show you what we're gonna do here. We'll loosen this up quite a bit. About like that. And then we'll take our ring terminal and you're gonna cut a small opening in it. And then with this being a little bigger, what I like to do is kind of pinch the ends closed again and then recut it out. It just kind of gets a better bite around it, I feel like. And we're just gonna slide this in like that. And then I'll just tighten the nut back down. Once this is tight, that's really all there is to it. And that'll finish up our look at and our installation of the Roadmaster battery charge line kit for towed vehicles on our 2022 Chevrolet Equinox..
I had this professionally installed and it didn’t work the way I thought it should. When my tow vehicle was hooked up to my RV and the RV wasn’t running the Tow vehicles battery would feed back into the RV and the radio, back up camera, and GPS would remain on in the RV. This would ultimately drain the tow vehicle’s battery. I ended up replacing this with an RVi unit.
OVERPRICED AND UNDER DELIVERED!
You get about 15 feet of wire worth 50 cents per foot and it is BARELY enough to get from the front of the vehicle to the battery. It works, but just go to Homer Depot and buy a spool of wire and two circuit breakers and you'll have enough to wire both the RV and the tow vehicle for 50% less. Do Not Recommend
I highly recommend this if you’re towing your vehicle behind a motorhome. We’ve gone across the country several times in the past year and I’ve never had a dead (or weak) battery on my Toad.
First off the chat rep sent me a complete list of everything that I would need to flat tow a 2015 Equinox so I made the $[XX]+ purchase from their list. After two full days installing all the items needed in the towed vehicle I try and attach it to RV and the connection can not be made. The tow bar will not fit into the base plate attaching points. I immediately (7/21) open a chat to let them know that they recommended the wrong parts and the rep agrees that a mistake was made and says that they will upgrade the shipping of the correct tow bar without charge so that I can have the tow bar a full day before my trip to test the complete install. I follow through with them after getting my order confirmation and it states that expected delivery is 7/22 so even though I needed to purchase a second two bar and wait for a refund on the first tow bar I am satisfied with the handling of the situation and comfortable with the full day to test the parts. On 7/22 I track the package only to see an expected delivery date of 7/23 so I immediately open up a chat and they proceed to tell me that there is nothing that they can do because it is already shipped. Then they go on to tell me that I agreed to 2-day shipping, which I did not. The previous rep told me that they would upgrade the shipping because it was their mistake. The normal Free Shipping is only a two day delivery to my area so an upgrade would mean next day shipping. I requested a full copy of the chat transcript to see where I specifically agreed to 2-Day shipping and they did not send me the transcript. I definitely regret giving this company my money. Their staff needs a lot more training to say the least. First they recommend the wrong parts so they are no expert in their field. Then they force me to purchase the replacement part fully knowing that the mistake was theirs. Then they can not follow through on their agreement to expedite the replacement part. Finally when confronted they proceed to put the blame on the customer as well as shrug their shoulders and say that there is nothing that they can do. Save yourself time, money and aggravation. Shop somewhere else where your business is actually appreciated.
The kit is fine. The install was for a 1997 jeep wrangler with a new roadmaster base plate. The red wire was approximately 12 inches short for wiring to battery. Had to buy red wire so I would have one piece without extra splice.
I’d highly recommend the charge line kit for anyone looking to tow for prolonged distances. No battery issues for me! Having the trickle charge gives me peace of mind as I tow. And one less thing to worry about is truly amazing. I used this for about 6 month on the road last year and am about to hit the road again. Love using products I feel confident with.
Victoria H.
3/21/2025
Thanks for your feedback Jenn! I'm happy to hear this adds more peace of mind to your adventures! Where to next?
Trailer people are the best! They assembled my replacement tow bar with this kit and it has worked perfectly ever since!
Brooke M.
5/9/2025
Right on! Where all have you been in the last year?
Easy installation in 2024 Ford F 150 XLT, all required connectors and wire are included
Easy to install, keeps my F150 battery charged up while flat towing behind my Motorhome
I purchased this as part of a package which included; Hitch and wiring for my 2022 Equinox, Base plate, Tow Bar, brake System and connecting air hose, break away cables, LED tow lights with wiring harness, and a trickle charger to keep the Equinox battery from going dead while I was towing it behind my class A RV.
I had etrailer do the install of all the components on my car and RV. All the workmanship was excellent and done in the amount of time they said it would take. Also because they did not have a video of this equipment being put on this year and model vehicle, I gave them permission to make a video(which added a extra day and a half to the install)and the installation was free. Everything has worked perfectly and I couldn't be happier. Etrailer is my go to for anything towing and also RV parts.
Jay
1/7/2025
I have had not trouble with battery on the Equinox which makes this all worth it. Etrailer lead me right
I ordered all the parts required to safely flat tow out 2017 Jeep Cherokee Trailhawk from etrailer.com. The only part they didn't have was the Mopar Flat Tow Enhancement kit Jeep requires to flat tow this model.
Ordering from them was great, the website is easy to use and I was able to locate all the pieces compatible with my specific vehicle. The expert recommendations help my decision choosing the right parts. I ordered from etrailer even though I found some of the parts on other websites a little cheaper. I chose to pay a little more because of all the effort etrailer has put into installation videos and guides. I was very pleasantly surprised to learn from etrailer that they have a price match guarantee!
So my equipment consisted of the following
Mopar Flat Tow Enhancement Kit (from Jeep)
Roadmaster Battery Charge Line Kit for Towed Vehicles
Mighty Cord 7-Way RV Style Trailer Connector - Trailer End
WesBarg 7-Way, RV-Style Connector w/ 6' Long Coiled Cable Trailer End
Pollak Black Plastic, 7-Pole, RV Blade-Style Trailer Socket - Vehicle End
Hopkins Custom Tail Light Wiring Kit for Towed Vehicles
SMI Stay-IN-Play DUO Supplemental Braking System
Roadmaster Brake-Lite Relay Kit for Towed Vehicles
Blue Ox Alpha Tow Bar - Motor Home Mount - 6,500 lbs
Blue Ox Base Plate Kit - Removable Arms
Blue Ox Tow Bar Cover - Aladdin, Aventa LX, Aventa II
The installation videos are great but not all inclusive. Take the time to read the instructions that come with the parts. This is a major project, I took about 30 hrs over a full week but as you'll see in the pictures I took s few extra steps to make a cleaner look.
Some of those extra steps:
The base plate install requires the bumper be modified cutting off a flange on each side, I spray painted this to prevent corrosion.
In the install video of the baseplate on the drivers side they use an extra quick link (not included) to run the safety cable around the wiper fluid reservoir. I took the time to remove it and run the safety cable behind it.
I didn't want our nice new vehicle to look like it can be towed so I played the brake away switch and 7 way trailer plug behind the license plate, so when not being towed our vehicle looks great!
Some things to be aware of. The Brake air cylinder that mounts to the brake pedal with four bolts may need longer bolts, it did on our Jeep. Spend the money for weather tight heat shrink crimp fittings. The Hopkins wire harness was about 1.5 feet short to get to my plug location. Buy extra zip ties, electrical tape and split loom.
I recommend reading all the various installation manuals and watching all the videos because the various components integrate together and if you install one at a time you'll be doing a bunch of extra work.
The brake light relay is a real pain in the butt, not because of the hardware but because of the location of the brake light switch which is very hard to get to.
Overall I am very happy with the products and how the installation looks. We haven't towed it yet but do not expect any problems.
Roy
7/30/2018
Still very happy with our purchase. We’ve towed over 10k miles and have had zero issues with our tow setup. I’ve shared my experience with several other RVrs and recommended your company for their needs. Thank you,
This product did exactly as described and was just what we needed to keep the battery charged in our towed vehicle.
Great service!
William
4/28/2025
This product has been working perfectly now for a year. No problems, thanks
have successfully completed the installation of the following items that I purchased from etrailer:
> Nighthawk RM-676 tow bar
> RM-524458-5 base plate
> DEMCO Stay in play DM86VR
> RM-152 diode wiring kit
> RM-156-25 charge wire kit
> RM-88400 brake switch relay kit
I work slow but methodically. I had no issues other than the high degree of difficulty for a 68 y/o man working alone. This project exceeds the abilities of someone NOT mechanically inclined. There is also the need for some specialty tools. I found that feeding the wiring through the dash, firewall, and underbody was more difficult than installing the front baseplate. Overall, I am satisfied with the function of this installation. I am glad I did it myself rather than having it done.
Tow vehicle: 2021 Entegra Emblem 36U
Towed vehicle: 2018 Ford Fusion Platinum Energi
Jeffrey
11/19/2022
I have no regrets with this purchase. Items preform as advertised with no issues. I am very satisfied with Roadmaster and Demco products.
I was told this would allow me to charge the battery on my 2025 Chevy Trax. You can only disconnect the negative battery terminal, not the positive battery terminal, so it will not work. Since the positive battery terminal is always connected and your motorhome provides the ground, you cannot isolate the battery - unless someone has come up with some sort of diode system.
It's working as far as I know. It was recommended by etrailer to add to my complete towing package. The installers put it in.I was glad for the quick helpful service fro etrailer when I asked questions about what I should get.
Good direction for installation easy to install.
Installation was straight forward no problems have not had a chance to tow our 2025 Maverick as I'm not done installing everything yet.
The Roadmaster brake connection kit has worked flawlessly on our toad. Thanks!
Richard
2/11/2025
Brake connection kit has worked fine with my Blue Ox system
The kit arrived without the fuse line. etrailer's excellent customer service took care of me quickly.
Brooke M.
4/4/2025
Glad we made it right!
Good instructions, easy to hook up.
I never knew I needed this for flat towing. Sales rep helped me pick the right item. Shipping was in a timely manner and the price was fair.
Victoria H.
1/9/2025
That's awesome Ron! I will let them know you reached out.
Easy fast installation. Works as advert ised
Simple an easy installation.
2018 Chevy Equinox LT, 1.5L Turbo. Product works perfectly and has for the last year. Always use etrailer.com to get it right. Tried to get the right products as a kit, but that was a total mess as the kits didn't even come close to what I needed. Called etrailer to get their expert opinion and it was great! For example, just for electric it took 3 different packages for the wiring. I also ordered the Blue Ox towing hardware including the car install and the tow bar. Used their videos for all the installations. Would not have gone well at all without their knowledge. Thanks etrailer!
Went ahead and installed this but with my setup on my Jeep, probably not necessary due to the fact ignition doesn't need to be on when towing. Jeeps don't have steering wheel lock.
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Nick S.
10/13/2025
This is definitely a part that is often forgotten, but makes the biggest difference! I am glad it is working well for you. Cross country?! Have you had any favorite spots you have hit?